Associations between specific antinuclear antibodies, detected by line immunoassay, and clinical features of patients with systemic lupus erythematosus

ABSTRACT

Autoantibodies are an integral part of the process of classifying, detecting, and, at least in some cases, mediating autoimmune diseases. The antinuclear antibody is not just one antibody but, actually, many different antibodies associated with a variety of diseases and disease manifestations. Antinuclear antibodies [ANA], anti-Sm, or anti-dsDNA antibodies are part of the American College of Rheumatology criteria [ACR] for SLE. Specific reactivities are associated with distinct clinical features of SLE. To study associations between antinuclear antibodies [ANA] detected by Line Immunoassay and signs/symptoms in patients with systemic lupus erythematosus [SLE]. A total of 38 unselected consecutive patients, diagnosed as having SLE and attending the rheumatology and nephrology units, Suez Canal University Hospital, were included in this study. The patients met the American College of Rheumatology [ACR] revised criteria for classification of SLE. ANA profiles were determined by line immunoassay and by indirect immunofluorescence on Crithidia luciliae. An extensive list of signs/symptoms was evaluated. ANA were found by indirect immunofluorescence [IIF] in 36/38 [95%] patients. The frequencies of the specific reactivities were anti-dsDNA 60%, anti-SmB 35%, anti-SmD 25%, anti-RNP-C 25%, anti-Ro60 15%, anti-SSB 15%, anti-RNP-A 10%, antiRibosomal P 10%, anti-Ro52 5%, anti Cenp-B 5%, anti Scl-70 2.6%, and anti-Histones 60%. Cutaneous manifestations were associated with anti-SSB, Ro52, Ribosomal P, anti-dsDNA and histones. Raynaud's phenomenon was associated with Ro52 and 60, histones and RNP-C. Xerostomia was associated with Ro52 and 60 as well as Cenp-B. Renal manifestations were associated with RNP-A, Ro52, Ro60 and dsDNA. By using a sensitive and specific multiparameter assay like LIA for identifying antinuclear reactivities, we could confirm some of the previously reported associations of antibodies with clinical symptoms of SLE. We also found several new associations meriting further study